• Title/Summary/Keyword: North Korean fisheries

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Migration and growth rate of Mottled skate, Beringraja pulchra by the tagging release program in the Yellow Sea, Korea (표지방류조사에 의한 참홍어 (Beringraja pulchra)의 이동 및 성장률)

  • Im, Yang-Jae;Jo, Hyun-Su
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.2
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    • pp.227-234
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    • 2015
  • To obtain geographical range and growth-kinetics parameters of mottled sake (Beringraja pulchra) populations in the Yellow Sea, three mark-recapture experiments were carried out. Overall, 991 tagged individuals were released, and 4.1% of them were recaptured with the mean release period of 339 d (range, 8-1,420 d) and the mean growth rate of $1.4cm\;mon^{-1}$ (female, $1.5cm\;mon^{-1}$; male $1.3cm\;mon^{-1}$). In the first experiment, 667 individuals were released at Heuksan Island from April to June, 2007-2009, and 30 individuals were recaptured mainly at the north and the north-east coasts of the island, indicating absence of migration to the south of the island. In the second experiment, 323 individuals were released at several fishing grounds scattered in the Yellow Sea in 2010-2013, and 11 individuals were recaptured at points deviated to all directions from the releasing points. As the last, one individual was released with pop-up satellite archival tag at a costal point ($34^{\circ}37.2$'N, $124^{\circ}59.3$'E) off Hong Island on May 21, 2010. The tagged individual migrated to a north-east location ($35^{\circ}50.4$'N, $126^{\circ}03.6$'E) of Eocheong Island by Aug. 25, 2010. The data archived for the three months in the tag indicated that the migration path had depths of 48-80 m and temperature of $12.6-14.4^{\circ}C$. The results indicated that mottled sake populations had a localized habitat ranges at the north of Heuksan Island and the west of Hong Island while growing at the rate of $1.4cm\;mon^{-1}$.

Physical and Acoustic Properties for Unconsolidated Sediment in the Kwangyang Bay: In Comparison with the Continental Terrace Sediment in the North Pacific (광양만 미고결 퇴적물의 물리적 및 음향학적 성질 : 북태평양 대륙붕 및 사면 자료와의 비교)

  • KIM Dae-Choul;KIM Gil-Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.24 no.5
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    • pp.289-302
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    • 1991
  • Laboratory determination of acoustic property for unconsolidated sediment of Kwangyang Bay was carried out. The compressional wave velocity was correlated to other physical properties and sediment textures to establish a geoacoustic model of the bay. The model was compared to the North Pacific continental terrace sediment. Velocity of the bay is systematically lower(0.02-0.04km/s) than that of the North Pacific. Average velocity of the bay is 1.521km/s. The lowest velocity is measured at the southwestern part of the bay. This area coincides with high amount of fine-grained sediment related to slower circulation. The overall tendency is, however, similar to the North Pacific continental terrace sediment.

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Water Distribution at the East Coast of Korea in 2006 (2006년 동해 연안의 수괴 분포)

  • Choi, Yong-Kyu;Jeong, Hee-Dong;Kwon, Ki-Young
    • Journal of Environmental Science International
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    • v.19 no.4
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    • pp.399-406
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    • 2010
  • Based on the Results of Annual Monitoring Report of Korean Marine Environment in 2006, it was shown that the coastal area of the East Sea around Korean peninsula could be clearly divided into two parts: the area of upwelling and the North Korean Cold Current. In the upwelling area, the chlorophyll-a and nutrients were increased by the influence of the decrease of temperature and the increase of salinity. These mean that the appearance of cold water due to the upwelling causes nutrient rich water and also resulted in the high productivity.

Physical Oceanographic Characteristics in Hupo Coastal area during Summer and Autumn, 2007 (2007년 하계 및 추계 경상북도 후포연악역 물리적 해황특성)

  • Hwang, Jae-Dong;Lee, Yong-Hwa;Shim, Jeong-Min;Young, Seok-Hyun;Jin, Hyun-Gook;Kim, Young-Suk;Kwon, Kee-Young;Yoon, Sang-Chol
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.6
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    • pp.505-510
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    • 2008
  • To understand the oceanographic characteristics of Hupo coastal waters as regards the East Korean Warm Current and the North Korean Cold Current, current direction and velocity were investigated by deploying a current meter in Hupo coastal waters during the summer and fall of 2007. Wind data were obtained from the homepage of the Korea Meteorological Administration. Water temperature was measured using a temperature meter attached to the current meter and a mini log. During summer, a south wind prevailed, while during the fall the wind blew from the north. Cold surface waters occurred on a large scale in summer, while in the fall, warm bottom water occurred frequently. After mid-November, when the surface water was cooler than $15^{\circ}C$, there was no difference in water temperature between the surface and bottom layers.

Three Dimensional Structure of the Ullung Warm Lens

  • CHO Kyu-Dae;BANG Tae-Jin;SHIM Tae-Bo;YU Hong-Sun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.4
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    • pp.323-333
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    • 1990
  • We studied the existence, form, size, variation and formation of warm lenses in the East Sea(Japan Sea) during $1979\~1988$ based on annual reports of oceanographic observations published by the National Fisheries Research and Development Agency of Korea and data of the Hydrographic Office of Republic of Korea. The warm lenses were formed in August, 1981, 1982, 1986 during study periods. The ranges of warm lenses were 50, 60, 90 km in the east-west(EW) direction and 100, 150, 120 km in the north-south(NS) direction in 1981, 1982, 1986, respectively. Because of the intrusion of cold water near 103 line, they shrink in horizontal scale in 1981. Most warm lenses were found at station 8 of 104 line in the vicinity of Ullung Island but centers of the lenses moved to the north in 1986. The form and position of warm lenses were related with the intensity of the Tsushima Warm Current and the formation of warm lenses were related with the bottom topography.

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The Terrain Transformation of the Fishing Industry in East Sea Rim: Impact of Entering Chinese Fishing Fleets into East Sea on the Fishery Production, Employment and Life Threat (환동해 어업의 지형 변화: 중국어선의 동해 진출이 어업생산과 고용 및 생존 위협에 미치는 영향)

  • Choi, Young-Jin
    • The Journal of Fisheries Business Administration
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    • v.52 no.1
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    • pp.1-22
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    • 2021
  • This study aims to face common threats from the depletion of fish resources, the decline of production and employment as well as the increase of life risk in East Sea Rim countries, North Korea, South Korea, Japan and Russia due to the Chinese fishing fleets entering East Sea. The recent competition in fishing among fishing vessels and fleets of national origin operating in the East Sea has induced a significant change in the ecological landscape of the fishing fleets cluster while having influenced production and employment in the fishing industries of South Korea and Japan as well as life threat on the fishermen in North Korea. It seems that the population organizational ecological theory can be applied to this change. It can be seen as the isomorphism of the selection process over the exclusive economic zone (EEZ) to avoid the environment in which these North Korean fishing vessels are pushed against the Chinese fleet in the North Korean part of the East Sea. To resolve the fishery disputes or conflict in the common waters in East Sea, first of all, Chinese fishing fleets will be required to put international pressure so as to solve the unfairness of the illegal fishing and overfishing by the International Fishery Organization or the UN violations of the sanctions against North Korea selling fishing rights to China. Although it is not easy for South Korea to cooperate with North Korea in the short term, South Korea will be able to support the fishery infrastructure in North Korea in the mid- to the long-term to prevent the loss of innocent lives for their fishermen and to raise their incomes.

Spatiotemporal Fluctuation of Water Temperature in Cheonsu Bay, Yellow Sea (천수만 수온의 시공간적 변동)

  • Choo, Hyo-Sang
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.1
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    • pp.90-100
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    • 2021
  • In the north and northeast of Cheonsu Bay, short-term fluctuations of surface water temperature are large owing to shallow water depth, weak current, and freshwater runoff. However, in the south of the bay, water temperature fluctuations are small owing to the inflow of offshore water by tidal currents. The water temperature in the north of the bay is higher in spring and summer than in the south of the bay, but lower in autumn and winter. During spring season, the fluctuation in the northern surface water temperature is the highest. The temperature fluctuations owing to tides are in phase with the tide in autumn and winter, and in the reverse phase with the tide in spring and summer. The dominant periods of water temperature fluctuations are half a day, daily, 15 days, and 1 month owing to the tide and 7 to 10 days, which are estimated based on atmospheric factors. Half a day and daily water temperature fluctuations are also highly correlated with air temperature and wind fluctuations. The sea area where water temperature fluctuations are highly correlated is divided into the north and south of the bay. The fluctuation phase is faster in the north of the bay than in the south or in the center.

Genetic positioning of Korean viral hemorrhagic septicemia virus (VHSV) from cultured and wild marine fishes

  • Kim, Wi-Sik;Jung, Sung-Ju;Kim, Jong-Oh;Kim, Du-Woon;Kim, Jeong-Ho;Oh, Myung-Joo
    • Journal of fish pathology
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    • v.24 no.1
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    • pp.1-9
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    • 2011
  • Viral haemorrhagic septicaemia virus (VHSV) is an epidemic virus in olive flounder Paralichthys olivaceus farms in Korea, since the virus have first isolated in 2001. In the present study, partial glycoprotein (G) gene nucleotide sequences of seven Korean VHSV from cultured olive flounder and wild marine fishes in coastal areas of Korea were analyzed to evaluate their genetic relatedness to worldwide isolates. Phylogenetically, all Korean VHSV formed only one minor cluster including Japanese isolates, in genotype IVa, while the North America isolates formed a different minor cluster in genotype IVa. These results suggest that Korean VHSV could be an indigenous virus in Korean and Japanese coastal areas, but have not been introduced from North America.